3 Answers

Theoretically, you would need 42. But, in real life, with flaws in wood, and the need to work around things...I'd say 45-46. You can always return what you don't use if you take care of it while it is in your possesion.

13 years ago. Rating: 3
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Just for the decking, no stairs, no top rails, you do need 42 boards 5/4" x 6" x 12'.  This is taking into account the grade as the best available.  If they are chosen carefully also, no splits, warps, or twists.  Good luck. 

13 years ago. Rating: 2
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5/4 x 6 boards are actually 5.5 inches wide. If you have 1/4 inch space between each, you will need at least 44 boards.

13 years ago. Rating: 1
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